Individual Disability-Adjusted Life Year: A Summary Health Outcome Indicator Used for Prospective Studies

Abstract:

In order to assess global health at individual level in prospective studies, a standard summary indicator of health – Individual DALY was established. It integrated all kind of disease into one measure, reflecting the healthy years lost during a period of time for an individual, with consideration of societal “ideal.”

Similar to Disability-Adjusted Life Year (DALY), Individual DALY used disability and disability weight to measure health problem and its severity after adjusting age and time preference. Following assumptions were made: (1) individual DALY be defined as the cumulated healthy life years lost for an individual during follow-up; (2) health status during a certain period of time kept stable, and the corresponding disabilities and disability weights could be assessed either by standard assessment tools during follow-up, or using the disease specific disability weights reported by Global Burden of Disease study, with the precondition that the synthetic disability weight of comorbidity had been resolved; (3) death be regarded as a special disability and assumed to be followed up until the end-point of follow-up. As a supplement to traditional population health assessment indicators, Individual DALY provides individual data and hence leads approaches in finding determinant factors of overall health more directly, evaluating effect of intervention more reasonably, and allocating health resource more effectively.

The calculation procedure, results, possible application and attentions were also illustrated using individual cases as an example.